The present invention is directed to electrical connector systems, and more particularly to connector systems that are employed to provide electrical connections with circuitry on printed wiring boards.
The increasing complexity of computers and other electrical equipment brings with it increasing demands on connector systems that are used with printed wiring boards in the equipment. Many signals may need to be conveyed between different printed wiring boards (which will hereafter be called PWCs), and considerable power may be drawn by the circuitry on the PWCs. The power demands of the PWCs and the number of signal connections that are needed typically differ from PWC to PWC.
FIG. 1 schematically illustrates a connector assembly 10 that includes a number of connector modules 12 which are mounted on an organizer 14. Different types of modules 12 are commercially available (for example, from Molex Inc., having an office at 2222 Wellington Court, Lisle, Ill. 60532, U.S.A.) for conveying power and signals. Each type of module is available in a male variety that is matable with a complementary female variety.
FIG. 2 shows examples of various commercially available male connector modules. The modules marked 12a, 12b, and 12d are typically used to transfer electrical power, and the module marked 12c is used for conveying signals. The module 12a, for example, includes a single contact conductor 16 (here, a blade) mounted on an insulating body 18. It is sometimes desirable for some of the connections to be made before other connections when a male connector assembly is mated with a complementary female connector assembly during a procedure called actuation. This can be accomplished by providing modules with different “mating levels,” so that the blades of some of the complementary module pairs mate before the blades of other complementary module pairs. As a result, the forces required for actuation frequently change along the length of engagement for the connector assembly 10 during the actuation process, with the center of force being dependent on which modules have engaged. The changing locations of the forces exerted on the connector assemblies during actuation produce moments (the product of force and distance) that may vary during actuation. This causes stress on the connector assemblies and the PWCs on which they are mounted, and can also cause a degree of misalignment of the blades themselves and thereby undermine the reliability of the connections. Moreover, the total required force that is needed during the peak mating level can easily exceed fifty pounds if the number of modules employed in a connector assembly is relatively large.